Read-only operations processing in a paxos replication system

A method, implemented at a computer system that includes one or more processors, for managing replication and storage of data by processing read-only operations, without storing the operations persistently, the method comprising:

• receiving a read-only request;
• determining an appropriate order defined by a determined execution slot for processing an operation for the read-only request;
• adding a no-earlier-than indication to the operation for the read-only request indicating that the operation is to be executed no earlier than the determined execution slot;
• determining one of the plurality of quorum members to serve as an appropriate replica which is determined to be best able to process the received read-only request;
• sending the read-only request and the determined execution slot and no-earlier-than indication to the appropriate replica, causing the read-only request to be executed at the determined appropriate replica by processing the operation for the read-only request, based on the slot and the no-earlier-than indication, at an execution slot that is later than the determined execution slot number, and without storing the operation persistently.

A computing system comprising at least one quorum leader for managing replication and storage of data by processing read-only operations, without storing the operations persistently, in a distributed computer system, the distributed computer system being operated under a Paxos-type protocol and including the quorum leader and one or more quorum members, the system comprising:

• one or more processors;
• and
• one or more computer-readable storage media coupled to the one or more processors, and having stored thereon computer-executable instructions that, when executed by the one or more processors, causes the computing system to perform the following:
• the quorum leader receiving a read-only request;
• the quorum leader determining an appropriate order defined by a determined execution slot for processing an operation for the read-only request;
• the quorum leader adding a no-earlier-than indication to the operation for the read-only request indicating that the operation is to be executed no earlier than the determined execution slot, wherein the operation is executed after the operation is committed, and wherein the operation is committed when at least half of the quorum members have both logged the operation and agreed to put the read-only request in the execution slot;
• the quorum leader determining one of the quorum members to serve as an appropriate replica which is determined to be best able to process the received read-only request;
• the quorum leader then sending messages to the quorum members to determine whether the quorum members have recognized a new quorum leader, and
• if not, sending the read-only request and the determined execution slot and no-earlier-than indication to the appropriate replica, and then executing the read-only request at the determined appropriate replica by processing the read-only operation of the request, based on the slot and the no-earlier-than indication, at an execution slot that is later than the determined execution slot number, and without storing the operation persistently;
• and
• if so, discarding any pending read-only request and the quorum leader then acting as a regular quorum member.